1. Field of the Invention
The present invention relates to a drain device for removal of condensate from an operational patient breathing circuit, and more particularly, concerns a continuously draining trap which allows condensate, but not gas, to drain from the patient breathing circuit while under pressure.
2. Description of the Prior Art
In respiratory therapy and anesthesia devices employed in patient breathing circuits for a variety of circumstances and reasons, various gases, air or vapors are delivered to the patient. For instance, mechanical ventilators are used to augment respiratory gas flow in circumstances where the patient may be experiencing respiratory failure. In these apparatuses, the breathing frequency and inspiratory and expiratory phases of ventilation can be varied by controlling the apparatus to meet the individual needs of the patient. Different ventilators may be employed also depending upon the condition of the patient: assisted ventilation is used in patients who have spontaneous respiration but who may have inadequate alveolar ventilation, whereas controlled ventilation is used in those patients with few or no spontaneous respirations. These ventilators will inflate the patient's lungs with air under pressure from the ventilator until either a preset pressure or preset volume, depending upon choice of apparatus, is achieved. When this preset level is reached, inspiration ends and expiration begins.
Similar devices are used on patients with chest diseases who receive Intermittent Positive Pressure Breathing (IPPB) treatments. An IPPB treatment may include the delivery of vapors to the patient in conjunction with a nebulizer in the patient breathing circuit. Delivery of the vapors is made to the patient by virtue of a closed breathing circuit, oftentimes under pressure, to assure proper delivery. In inhalation anesthesia circuits, the gas mixtures are also delivered to the patient under pressure in accordance with the proper control mechanisms.
One of the problems which occur in both pressurized and un-pressurized gas or vapor delivery systems involves the undesirable collection of condensate generally in the tubing which extends from the control apparatus to the patient. This condensate occurs since these gases or vapors in the line contain a certain amount of humidity before entering the patient. Once condensation starts to build up in the line, it must be removed to improve patient comfort and also to prevent the patient from inspiring too much water. Water traps in these patient breathing circuit lines have been in existence for some time, but are deficient in many respects. For instance, the known water traps tend to collect water within and must be drained about every hour. Some of these water traps are very large and increase the compressible volume of the patient circuit. When filled with water, they add a considerable amount of strain to the circuit caused by the weight of the accumulated water. Some of the smaller volume water traps tend to lose effectiveness by dumping water back into the patient circuit if the patient should move or pull the tubing. These smaller volume traps also must be drained more frequently. When draining occurs in both small and large existing water traps, the patient circuit, if operating under pressure, must be shut down and depressurized when the water is being emptied from the trap. Of course, during the depressurized condition, delivery of the gas, air or vapors to the patient is interrupted.
It can be seen that manual draining of the existing traps is time consuming and requires periodic monitoring by the attendants to observe when the trap is becoming filled. In addition, the interruption of the service to the patient during depressurization of a pressurized patient breathing circuit is undesirable. With these major problems in mind, there has been a need in this field of patient breathing circuits to provide a water trap or draining device which will simplify the tasks of the respiratory therapist while at the same time improving inhalation service to the patient. It is to this end that the present invention is directed.